Process for production of molded polyester resin article, crystallization inducer for use in the process, master batch, and molded polyester resin article

Abstract

This invention provides a process for producing a crystallized polyester resin molding. The process includes melting and injecting the below-described first or second compound (a) or (b) into a mold and holding the same in the mold, and then conducting cooling to crystallize a polyester resin of a resulting molding without using an inorganic nucleating agent: (a) a first compound of a crystallization-inducing crosslinked polyester resin, in at least a portion of which crosslinked points have been formed with a crosslink forming agent, and a first non-crosslinked polyester resin; or (b) a second compound of a crystallization-inducing master batch, which comprises the crosslinked polyester resin and a second non-crosslinked polyester resin and abundantly contains the crosslinked polyester resin, and the first non-crosslinked polyester resin. According to the present invention, a crystallized polyester resin molding free from impairment of translucency or transparency can be produced without using an inorganic nucleating agent that would produce haze in the molding.

1 . A process for producing a crystallized polyester resin molding, comprising melting and injecting the below-described first or second compound (a) or (b) into a mold and holding the same in the mold, and then conducting cooling to crystallize a polyester resin of a resulting molding without using an inorganic nucleating agent:
 (a) a first compound of a crystallization-inducing crosslinked polyester resin, in at least a portion of which crosslinked points have been formed with a crosslink forming agent, and a first non-crosslinked polyester resin; or   (b) a second compound of a crystallization-inducing master batch, which comprises the crystallization-inducing crosslinked polyester resin and a second non-crosslinked polyester resin and abundantly contains the crystallization-inducing crosslinked polyester resin, and the first non-crosslinked polyester resin.   
     
     
         2 . The process according to  claim 1 , wherein a crosslinking polyester resin, which is the crystallization-inducing crosslinked polyester resin before crosslinking, the second non-crosslinked polyester resin and the first non-crosslinked polyester resin may be the same or different, or a mixture thereof. 
     
     
         3 . The process according to  claim 2 , wherein the crosslinking polyester resin, the second non-crosslinked polyester resin or the first non-crosslinked polyester resin is a polycondensation product of at least one hydroxy aliphatic carboxylic acid, a ring-opening polymerization product of at least one aliphatic lactone, or a polycondensation product between at least one aliphatic polycarboxylic acid, alicyclic polycarboxylic acid or aromatic polycarboxylic acid and at least one aliphatic polyol, alicyclic polyol or aromatic polyol; or a random co-condensation polymerization, block co-condensation polymerization and/or graft co-condensation polymerization polyester resin thereof. 
     
     
         4 . The process according to  claim 3 , wherein the hydroxy aliphatic carboxylic acid has a carbon number of from 1 to 18, the aliphatic lactone has a carbon number of from 3 to 6, the aliphatic polycarboxylic acid has a carbon number of from 2 to 10, the alicyclic polycarboxylic acid has a carbon number of from 4 to 10, the aromatic polycarboxylic acid has a carbon number of from 6 to 12, the aliphatic polyol has a carbon number of from 2 to 6, the alicyclic polyol has a carbon number of from 4 to 10, and the aromatic polyol has a carbon number of from 6 to 12. 
     
     
         5 . The process according to  claim 4 , wherein the crosslinking polyester resin, the second non-crosslinked polyester resin or the first non-crosslinked polyester resin is a polyester resin of lactic acid, succinic acid, hydroxybutyric acid and/or hydroxyhexanoic acid as a constituent component. 
     
     
         6 . The process according to  claim 1 , wherein the crosslink forming agent is a radical generator and/or a polyfunctional crosslinking agent. 
     
     
         7 . The process according to  claim 6 , wherein the radical generator is at least one peroxide selected from peroxycarbonates, peroxyesters, diacyl peroxides, dialkyl peroxides, peroxyketals and hydroperoxides. 
     
     
         8 . The process according to  claim 6 , wherein the radical generator is at least one azo radical generator selected from 1,1′-azobiscycloalkanecarbonitriles, 2-(carbamoylazo)alkylnitriles and 2-phenylazo-4-alkoxy-2,4-dialkylalkylnitriles. 
     
     
         9 . The process according to  claim 6 , wherein the polyfunctional crosslinking agent is at least one polyfunctional compound selected from polyepoxy compounds, polyisocyanate compounds, polymethylol compounds and polycarbodiimide compounds. 
     
     
         10 . The process according to  claim 1 , wherein the compounding ratio of the second non-crosslinked polyester resin to the crystallization-inducing crosslinked polyester resin is from 0.05 to 10 parts by weight of the second non-crosslinked polyester resin per parts by weight of the crystallization-inducing crosslinked polyester resin, and the compounding ratio of the first non-crosslinked polyester resin to the crystallization-inducing master batch is from 1 to 100 parts by weight of the first non-crosslinked polyester resin per parts by weight of the crystallization-inducing master batch. 
     
     
         11 . The process according to  claim 1 , wherein the compounding ratio of the first non-crosslinked polyester resin to the crystallization-inducing crosslinked polyester resin is from 3 to 100 parts by weight of the first non-crosslinked polyester resin per parts by weight of the crystallization-inducing crosslinked polyester resin. 
     
     
         12 . The process according to  claim 1 , wherein the mold has a temperature of a crystallization temperature Tc of the melted resin mixture ±30° C. during the molding, and the resin is held for a time of from 5 to 240 seconds in the mold. 
     
     
         13 . The process according to  claim 1 , wherein in any one of a preparation step of the crystallization-inducing crosslinked polyester resin, a preparation step of the crystallization-inducing master batch, a preparation step of the first or second compound (a or b) and the molding step of the first or second compound (a or b), at least one additive selected from colorants, dispersants, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, antistatic agents, fillers, addition-polymerizable monomers and chain extenders is added. 
     
     
         14 . A crystallization inducer for an amorphous polyester resin, which is obtainable by causing a crosslink forming agent to act on a crosslinking polyester resin, which is a crystallization-inducing crosslinked polyester resin before crosslinking, to form crosslinked points in at least a portion thereof. 
     
     
         15 . A crystallization-inducing master batch for a polyester resin, comprising a non-crosslinked polyester resin and the crystallization inducer according to  claim 14  as spread in the non-crosslinked polyester resin. 
     
     
         16 . A compound for a polyester resin molding, comprising the crystallization-inducing master batch according to  claim 15  and another non-crosslinked polyester resin kneaded together, wherein the compound is free of an inorganic nucleating agent. 
     
     
         17 . A compound for a polyester resin molding, comprising a non-crosslinked polyester resin and the crystallization inducer according to  claim 14  added in the non-crosslinked polyester resin, wherein the compound is free of an inorganic nucleating agent. 
     
     
         18 . A crystallized polyester resin molding obtainable by molding a non-crosslinked polyester resin and the crystallization-inducing master batch according to  claim 15  added therein, wherein the molding is free of an inorganic nucleating agent. 
     
     
         19 . A crystallized polyester resin molding obtainable by molding the crystallization inducer according to  claim 14  and another non-crosslinked polyester resin, said crystallization inducer being added in said another non-crosslinked polyester resin wherein the molding is free of an inorganic nucleating agent.